Vehicle safety device

ABSTRACT

A vehicle safety device comprising an expandible composite element provided with a mounting for location in a vehicle and which is expandible from an inoperative retracted position to an operative expanded position, and means for rapidly filling the element with a filler material to cause the expansion, the element including an outer shield which expands first and an inner shield which extends inwardly therefrom the expansion of which is commenced after expansion of the first shield has started.

United States Patent 1191 Gorman 5] Aug. 21, 1973 VEHICLE SAFETY DEVICE3,663,037 5/1972 -Wohn-MacHowski 280/150 13 3,643,972 2/1972 Caiati etal 280/150 8 [76] Invent: Mm Cmer (Image 3,511,519 5/1970 Martin 280/150AB The Street Effingham Surrey, 3,606,377 9/1971 Martin 280/150 ABEngland 2,672,628 3/1954 Spanel 5/348 R Saunders B [21] Appl' 184834Primary Examiner-Kenneth H. Betts Assistant Examiner-John P. siiverstrim52 U.S. c1. 280/150 AB, l28/D1G. 2, 297/390 Attorney-Donald Wight et[51] Int. Cl. B601 21/08 [58] Field of Search 280/150 AB; 5/348 R;

l28/D1G. 20; 182/137; 297/390 [57] ABSTRACT A vehicle safety devicecomprising an expandible com- References Cited posite element providedwith a mounting for location UNITED STATES PATENTS in a vehicle andwhich is expandible from an inopera- 3 675 942 7/1972 Huber 280,150 ABtive retracted position to an operative expanded posi- 3:588'l42 6/1971280,150 AB tion, and means for rapidly filling the element with a3,218I103 11/1965 Boyce 128 D1o.20 filler material cause the expand, theelement. 3,5 2,107 971 Goat; at 230/150 AB eluding an outer shield whichexpands first and an inner 3,672,699 6/1972 De Windt 280/150 AB shieldwhich extends inwardly therefrom the expansion 2,834,606 5/1958 Bertrand280/150 AB of which is commenced after expansion of the first 2,806,7379/1957 Maxwell .9 280/150 AB X shield has started. 3,603,430 9/1971Kendall et aL. 182/137 3,614,127 10/1971 Glance 280/150 AB 22 Claims, 16Drawing Figures l Y 10 U 6 Patented Aug. 21, 1973 3,753,576

6 Sheets-Sheet 1 Patented Aug. 21, 1973 6 Sheets-Sheet 5 Q N a a a 5 mml NN m mm mm Q u R N am N a mN mm Q Q R Patented Aug. 21, 1973 6Sheets-Sheet 5 6 Sheet s 6 1 VEHICLE SAFETY DEVICE This inventionrelates to a vehicle safety device to provide injury protection for theoccupant or the structure of a wheeled or other vheicle and is basedupon the general principle of providing a rapidly produced protectiveshield which can act to cushion the impact of the structure or theoccupant against a colliding object.

According to one aspect of the present invention a vehicle safety devicecomprises an expandible composite element provided with a mounting forlocation in a vehicle and which can be expanded from an inoperativeretracted position to an operative expanded position and means forrapidly filling the element with a filler material to cause theexpansion, the element including an outer shield which expands first andan inner shield which extends inwardly therefrom and expansion of whichis commenced after expansion of the first shield has started.

Thus, with this construction the element can be arranged to extendaround a passenger to be protected to encapsulate him and the innershield then expanding inwardly and closely contact him.

Conveniently the safety device may be rigidly secured to a vehicle seatand may include the main structural member part of which extends abovethe back of the seat and which carries the expandible element.

The main structural member above the seat may provide a safety structureto prevent the vehicle structure from caving in around the seat in theevent of damage to it.

With this arrangement the main structural member may be in the form of ahoop from which the element expands forwardly around the seat to a partspherical shape, the inner surface of the inner shield being contouredto approximate to the frontal and side shape of a human body from thehead down to the waste level when the element is fully expanded.

The filler material may be gas or a foam solution and the protectivecompsiteelement may be constructed from plastic or other fibrousmaterials or a combination of both.

Preferably means are included for delaying the expansion of the innershield until the outer shield is at least partially expanded andseparate pressure sources may be provided to expand the inner and outershields.

Preferably the filler material is a gas carried in a capsule or capsuleslocated in the mounting and these capsules may be conveniently carriedin a head rest provided in the mounting.

In any case, the outer shield may be made up from a series of tubes towhich the inner shield which comprises a series of vesicles isconnected.

Means are also preferably provided for releasing the expandible elementfrom its mounting after it has been expanded and means may also beincorporated for operating the release means after a time delay.

The expandible element may be carried by an anchorage member which isreleasably secured to attachment means in the mounting and which can bereloaded with a replacement anchorage member and element after theoriginal element has been operated and removed.

In a preferred embodiment the expandible element is located in a housingwhen in its retracted position, the housing being closed by a removablecap and means may be provided for releasing the cap as the element isexpanded.

With this contruction the interior of the housing is preferablypressurised prior to releasing the cap and the pressurisation may beprovided by filler material used to expand the outer shield.

The element may be perforated to provide passage for air/light so thatwhen it is in position around the passenger these essentials areprovided.

Thus, the element may have light transmitting fibres which extendthrough it and which are arranged for viewing at a predetermined zonewithin the element.

In any case, the outer shield may carry reinforcing bands at its edgearea and the mounting may carry an impact cushion which is expandible inthe opposite direction to the element to provide protection to theelement to provide protection for a person behind the safety device.

Preferably a sensor operated by acceleration or deceleration, rate ofdecent in the case of an aircraft, pressure or heat is provided whichactuates a signal generator to cause operation of the device and thesensor may include a piezo crystal which is subjected to mechanicaldeformation in well known manner.

The single generator can be arranged to actuate a signal interrupter orchopper which performs a time delay in a sequence of signals foractivating the operating means and the device may also include a monitorwhich allows operation of the operating means only at predeterminedconditions of vehicle motion so that, for example, the device cannot beoperated when the vehicle is stationary.

Means may also be included for preventing operation of the device ifthere is no occupant With these arrangements therefore a manualoperating device could be included which actuated the piezo crystal suchas the brake pedal of a motor vehicle and the sensing device could beincorporated in a vehicle speedometer so that the filler means is onlyactuated at predetermined speeds and brake fluid pressures. In anaircraft the sensing device could be incorporated in a rate of descentmeter or in an accelerometer.

This invention may be performed in various ways and one embodiment asapplied to a motor vehicle will now be described by way of example andwith reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic side elevation partly in section of a safetydevice according to the invention and incorporated in a motor vehicleseat,

FIG. 2 is a rear elevation of the seat shown in FIG.

FIG. 3 is a front elevation of the same seat,

FIG. 4 is a plan view of the seat shown in FIGS. 1 to FIG. 5 is apartsection through the line 55 in FIG. 1,

FIG. 6 is a part cross sectional view on the line 6-6 of FIG. 4,

FIG. 7 is a scrap view on the line 77 of FIG. 6,

FIGS. Sand 9 are part cross sectional views on the lines 8 and 9respectively of FIG. 2,

FIG. 10 is an enlarged part cross sectional view on the line 10-10 ofFIG. 2,

FIG. 11 is an enlarged view of part of FIG. 9,

FIG. 12 is a fragmentary view of the gas supply manifold,

FIG. 13 is a part cross sectional view of the expandible element whenexpanded,

FIG. 14 is a diagrammatic cross sectional view showing the location ofair holes and light fibres,

FIG. 15 is an isometric view of an intermediate anchorage member, and,

FIG. 16 shows the electric operating circuit for the apparatus.

As shown in the drawings the safety device is incorporated in the seatstructure of a motor vehicle which is indicated in FIG. 1 by thereference numeral 1.

The principal by which the passenger is to be protected is encapsulationin two stages. The primary stage is extremely rapid and consists of ageneral envelopment of the upper parts of the body by a compositeelement indicated by reference numeral 2 emanating from a housingindicated generally by reference numeral 3 situated behind the passengerwho is indicated in the drawings by reference numeral 4. This housing 3follows the general line of the body from the waist position on the oneside around the head to the waist on the opposite side. The compositeelement is a tough pliable construction of inner and outer layers. Thespace between contains ducts, indicated generally by reference numeral 5(shown in FIG. 5) which are pressurized during operation to open theprotective envelope and move it into its operative extended position.These ducts 5 run from distribution channels 7,8 carried within thehousing 3 to the extremeties of the element 2. The secondary stage ofencapsulation takes place when ducts 6 which are in the form oflocalised areas on the inside of the protective element expand andclosely contact the passenger as is most clearly shown in FIG. 1. Asthese continue to fill out under pressure the passenger is pushed backinto his seat with his body being centralised. Some of the ducts 6expand inwardly so that they contact the sides of his head and neck andthe rear of his head contacts a head rest indicated generally byreference numeral 9. On frontal or sideways impact being subjected tothe vehicle in which he is travelling, he will initially move from hisseat, only against resistance of the pressurised protective element,subsequently against the resistance to stretch of the material fromwhich the element is constructed.

- The pressurising medium may be a gas or a foam solution and in thearrangement being described a gas is used and the protective element maybe constructed from plastic, or fibrous material or a combination ofboth. Certain strengthening material may be contained within theconstruction of the protective element to limit stretch and resistrupture and part of the protective element may be provided with cellularinteriors and locally enlarged, for added safety. The secondary stage ofexpansion is delayed until the primary stage is partially completely,and uses a separate pressure source working in conjunction with theprimary source.

The pressure sources and reservoirs are indicated be reference numeral10 and are carried in the head rest 9, suitable delivery ducts to theelement 2 being provided in a manifold 11 which is to be described.

A hoop shaped main structural member 12 surrounds the seat and isconnected to a base 13 to which theseat l is also rigidly connected sothat adjustment of the seat simultaneously adjusts the main structuralmember 12. The main structural member 12 is of channel section and itsouter surface is covered with protective padding 14 as is most clearlyshown in FIGS. 8 and 9. The upper part of the member 12 extendssubstantially vertically and is provided with a liner channel 15 madefrom a hard plastics material. Secured to the lower wall of the channelsection member 12 is an intermediate anchorage member 16 part of whichis most clearly shown in FIG. 15 and which is secured by rivets 17. Theintermediate anchorage member 25 is cut back at 17 to provide anenlarged head 18 to which is connected a main anchorage member 19 madefrom a hard but resilient plastics material. This member 19 extendsaround the housing in a similar manner to member 16 and is locked ontoit by abutments 20 which engage beneath the cutback portions 17 of themember 16, and which are assisted by intensifier springs 201. The sideportions 21 of the member 19 engage and seal against the liner channel15 and the cross sectional shape of the member 19 forms the main part ofthe gas distributor ducts 7 and 8. The front face of the main anchoragemember 19 is provided with a serrated surface 22 against which aplastics material gripper member 23 having a similar surface is clampedby means of screws 24 which engage metal inserts 25 in the grippermember. A series of screws extend throughout the length of the grippermember to provide adequate attachment.

Membrane attachments 26 are provided on the expandible element, enterthe interstice between the serrated surfaces where they are firmlyclamped into positron.

The expandible element 2 comprises inner and outer shields which areoperated respectively by the ducts 5 and 6. The outer shield comprises aseries of tubes 27 each of which is attached to the anchorage member 21by passing through flattened openings 28 and 29 in the anchorage member19 and gripper member 23, the shape of these openings being indicated inFIG. 7. Each tube terminates by being firmly clamped by a tapered formplug 30 which is retained by a screw 31 passing through a lug at eachend of each plug, the screws engaging screw threaded holes in theanchorage member 19. There are a number of outer tubes and they areconnected to an outer membrane covering 32 which joins them all togetherand which provides the diaphragm 26 which is gripped by the grippermember 23. This membrane is reinforced with additional layers of similaror other materials. The tubes 27 have attached to them tubes 33 whichform the inner shield, these tubes 33 being in the form of vesicles whenexpanded and which are folded in the manner shown by broken lines 34 inFIG. 6 prior to opening. Each of the tubes 33 passes through openings 35and 36 in the members 19 and 23, these openings being similar to theopenings 28 and 29 but spaced away from them. The ends of the tubes 33which provide the vesicles 34 are clamped by tapered plugs 37 which areheld by screws 38 in a similar manner to the tapered plugs 30 describedabove. It will be appreciated that the tubes 27 open into the gas ducts7 and the tubes 33 into the gas duct 8.

Attached to the vesicles 34 at a location near to gripper 32 and themembrane attachments 26 and which also extend between the serratedsurfaces, on the members 19 and 23 where they are firmly clamped. Thus,with all the principle elements of the inner and outer shields firmlyclamped to the shield anchorage member 19, the operational stressesimparted to the shield are transmitted to the shield anchorage memberand through the subsidiary anchorage member 16 to the main structuralmember 12.

When the device is assembled the expandible element 2 is foldedconcertina fashion, as shown in FIGS. 8 and 9, into the housing and isheld in place by a cap 40, and is made from a suitably rigid plasticsmaterial. The inner ends of the cap are provided with rim latches 41which engage behind the walls of grooves 42 provided in the member 19.The walls of the cover 40 also engage dimples 181 provided on thechannel section main structural member 12. Arranged beneath the latches41 are expandible release bladders 43 to which the gas can be fedthrough T-junction pieces 44 (see FIG. which extend into passages 45provided in the member 19. The passages 45 are aligned with passages 46carried in blocks 47. The blocks 47 each have a bore 48 which locates ona tube 49 extending through the rear wall of the main structural member12 and passing through the secondary anchorage member 16. Thecontruction of the blocks 47 is most clearly shown in FIG. and it willbe seen that the upper surface of the block is provided with serrationsto assist in easy loca tion and to reduce gas escape. If desired theblocks may be cemented into position, the cement being such that it willpart and allow the blocks to be removed in a manner to be explained.

The tube 49 extends rearwardly to the manifold 11 and from FIG. 12 itwill be seen that the manifold is arranged immediately behind the mainsupport member 12 and carries four gas storage capsules and the deliverypipes for delivering the gas from them to the various parts of thedevice.

In order to operate the device an electrical impulse is generated, bymeans to be described, which detonates a small explosive charge (notshown) to rupture a sealing diaphragm (not shown) in the storage capsule50 indicated in FIG. 12. This storage capsule, which is connected to themanifold 11 passes gas through a delivery nozzle 51 on the manifold 11to the gas distributor channel 7, the nozzle 53 passing through openingsin the wall of the main structural member 12 and in a liner 15. The gasis directed from the channel 7 into the outer shield by passing throughthe plugs 30 and into the tubes 27. Some of the gas passes through aseries of passages 52 to a centre channel.53 formed in the shieldanchorage member 19 and through a valve 54 to transverse grooves 55formed behind the gripper member 23 and into the interior of the cap 40where it causes a sharp rise in pressure causing a tendency for the capto eject from the housing. The cap 40 is provided with a number of gasleakage paths 56 which promote pressure equalisation between the insideof the cap and the interface between the cap and its housing.

A second electrical impulse detonates a further small explosive chargeto release gas from a small storage capsule 57 on the manifold 11 whichgas is directed through the manifold to the gas entry probe 49. The gasrelay block 47 transfer the gas to the bladders 42 causing them toinflate and thereby disengage the dimples on the main structural memberand rim latches 41. This engagement of the latches from the shieldanchorage member allows the cap 40 to be freed and ejection followsinstantly due to the raised pressure inside the cap, with frictionforces tending to retard ejection minimised due to the air gap producedat the cap and housing interfaces by the openings 56. Due to the form ofthe cap and the concertina method of folding the stored expandibleelements within it the element is carried some distance with the cap asit ejects.

The movement of the folded element away from the housing causes adetection head 58 (see FIG. 9) to move outwards under the influence of aspring 59 and through a valve spindle 60 to close the valve 54 toprevent the further supply of gas through the transverse grooves 55. Thefull flow of gas from the storage capsule 50 is now directed into thetubes 27 which provide the outer shield. Thus, the outer shield expandsout to an eliptical form, as shown in FIG. 1 and to progressively openout the concertina folds in the tubes as expansion progresses alongthem. This action carries on the initial momentum gained by ejection ofthe cap 40 and continues until the tubes are all opened-out to theeliptical form. The construction of the tubes and their assemblytogether results in the shape produced by the expanded and developedtubes this being similar to a part spherical shell that is, with thedepth of the eliptical tubes equivalent to the thickness of the shell.As the shape develops the tubes 27 carried with them the outer membranecovering 32 and also the inner tubes 33 which provide the vesicles 34 inunexpanded form and it is only during the time after they have alreadycompleted part of their movement with the tubes do they begin to receivea supply of pressurised gas which causes them to expand away from thefolded formation indicated by broken lines 34 towards a point that isapproximately the centre of the spherical shape of the fully formedshield outer element. The gas required to bring about the unfoldingexpansion of the inner shield is from a further gas storage capsule 58again carried on the manifold 11 which transvers the gas through adelivery nozzle 59 which enters the main structural member 12 through anopening and into gas distributor channel 8 serving the inner element.The gas is directed from the channel into the tubes 33 through thetapered wedge fittings 37.

Due to the method of attachment the loads on the shields are transferredto the main structural member 12 through the intermediate anchoragemember 16 and the stress of operation are transferred through theabutments 20 which are held in positive engagement by the naturalresilience of the shield anchorage member 19 and intensifier springs201, the engagement being further promoted by inclinations of theabutment surfaces which act to cause riding up of the shield anchoragemember abutments on the root anchorage abutments and forces tending toseparate the two members occur. Should assymmetric arise in operation,where for example, the outer membrane 26 is transferring most of 1 thestresses back to the shield anchorage members, the gas channel outerwalls 21 reacting against the main structural member liner 15 tostabilise the shield anchorage member against distortion.

To resist the effects of operational stress which would tend to rupturethe shield along its lower level, corresponding the waist level of theseat occupant to which the safety device is fitted, a reinforcing band61 is provided which tends to give a lap belt effect. These reinforcingbands 61 are also employed to close and pressure seal the tubes in theshields.

After operation release of the shield assembly is effected by theinflation of a set of bladders 62, most clearly shown in FIG. 10 whichact through the ends of the springs 60 to disengage the abutments 20formed on the anchorage member 19 from the member 16. The spring 60 alsoprovides a low friction surface from the shield anchorage member 19 toslide on when the shield anchorage member is withdrawn from the mainstructural member and out of the liner channel 15. The inflating gas tothe bladders 62 is released from the gas storage capsule 63 carried onthe manifold 11 by the rupture of a sealing diaphragm caused by thedetonation of a small explosive charge fired by an electrical impulse.The gas is directed from the storage capsule through the manifold l1 andis then conducted by a supply probe 64 through an opening in the mainstructural member 12 to a gallery 65 formed in the root anchorage member16 (see FIG. into which the bladder terminations enter in the form oftee fittings 66. Shield release is assisted by the gas pressureexhausting in the gas distributor channels, 7, 8 which tend to separatethe shield anchorage member 19 from the liner channel 15.

Whilst the shield is in the operational position, the seat occupant towhich the safety device is fitted is enabled to see out of the vehicleby means of light transmitting fibres 77 which are arranged in groups toreceive light sources within the shield and which project through amember of particular eyelet holes in the shields, these eyelets 78provide attachment zones for the inner and outer shields and areorientated by the shield when it is in its operative position. Some ofthe eyelets may be open as shown at 79 to allow the entry of air.

In the arrangement shown in FIG. 14 air holes are indicated by referencenumeral 80 and a number of light transmitting fibres 81 are providedwhich lead to a viewing panel 82 within the shields.

As will be seen from FIG. 1 the various capsules connected to themanifold 11 are located within the head rest 9 and thus, when theapparatus has been operated and the shields released a new operatingelement can be fitted and made ready for use merely by replacing thecapsules and fitting a replacement anchorage member 19. The element isnow folded concertina fashion and the cap 40 placed in position.

The electrical impulses which detonate the small explosive charges torupture the sealing diaphragms of the gas discharge capsules arecontrolled from a triggering or signalling circuit which is showndiagrammatically in FIG. 15. This circuit senses whether certainpredetermined conditions of motion or compounds of different motionstogether with other conditions of pressure in, say in braking systemhydraulic lines, or by direct intervention of a human agency usingspecific control. As will be seen the circuit comprises a source ofelectrical power 100 which can be derived from the vehicle power supplythe electrical power source passing to each of four seating positions inthe vehicle. From these detectors 101 the power supply passes to aseries of sequence controllers 102 and then to the cartridges on the gasstorage capsules. From FIG. 12 it will be seen that an electrical supplysocket 103 is carried on the manifold 1], suitable wiring beingprovided. A sensor which is sensitive to acceleration, deceleration,rate of descent in the case of an aircraft, and electrical impulse whichcan be operated from a manual control or a sensor operated by heat isindicated at 104. This sensor may contain a piezo electric crystaloperated in known fashion and which can be arranged to be operated by,for example, a motor vehicle brake control. This sensor is connected toa signal generator 105 a signal from which passes to a signal amplifier106 and a monitor 107. The monitor 107 is a simple electrical de vicewhich is arranged to keep the circuit inoperative unless certainpredetermined conditions are in operation. For example, in a motorvehicle the device could be arranged to be non-operative unless thevehicle is moving beyond a certain speed thus preventing inadvertentoperation of the safety devices if the vehicle was stationary.

A discretionary control 108 is also provided which can be manuallyoperated to fire the devices and it will be seen that this can overrideall the other controls apart from the vehicle seat occupancy detectors101. The signals pass to a relay 109 and then to a line 110 to thesequence controllers 102. The sequence controllers may be of anyconvenient form well known in electrical applications, for example acondenser, so that they issue a series of sequential pulses which arepassed to the cartridges, indicated by reference numerals 11 1. The gapbetween each pulse can be determined by experiment and will be in theregion of one tenth of a secend.

It will be appreciated that the control system set out above is onlytypical of many which can be used with the device.

As will be seen from FIG. 1 the rear of the head rest is also providedwith an expandible element indicated by reference numeral 112. Thiselement is also arranged to operate simultaneously with the shields toprovide protection for any passenger behind the seat carrying the safetydevice. This element 1 12 can be operated by gas from the storagecapsule 58 through a rearwardly extending probe 13 on the manifold 11 orfrom a further capsule connected to the probe 113.

I claim:

1. A vehicle safety device comprising an expandible composite element,mounting means for mounting said element in a vehicle-in an inoperativeretracted position relative to an occupant seat, said element includingan expansible and projectable outer shield carried by said mountingmeans for projection therefrom, means connected to said outer shield forexpanding said outer shield and projecting said outer shield to ashielding position in spaced relation to an occupant seat to provide fora initial shielding of an occupant, said element also including an innershield carried by said outer shield for projection therefrom, and meansfor expanding said inner shield relative to said outer shield towards anoccupant seat after expansion of said outer shield has been initiated toprovide for a further shielding of an occupant.

2. A vehicle safety device as claimed in claim 1 in which the element isarranged to extend around an occupant to be protected to encapsulatehim, the inner shield expanding inwardly to closely contact him.

3. A vehicle safety device as claimed in claim 2 wherein said mountingmeans is rigidly secured to a vehicle seat.

4. A vehicle safety device as claimed in claim 3, said mounting meansincluding a main structural member part of which extends above the backof the seat and which carries the expandible element.

5. A vehicle safety device as claimed in claim 4 in which the mainstructural member above the seat provides a safety structure forpreventing the vehicle structure caving in around the seat.

6. A vehicle safety device as claimed in claim 5 in which the mainstructural member is in the form of a hoop and from which the elementexpands forwardly around the seat to a part spherical shape, the innersurface of the inner shield being contoured to approximate to thefrontal and side shape of a human body from the head down to waist levelwhen the element is fully expanded.

7. A vehicle safety device as claimed in claim 1 in which the fillmaterial is a foam solution.

8. A vehicle safety device as claimed in claim 1 including means fordelaying expansion of the inner shield until the outer shield is atleast partially expanded.

9. A vehicle safety device as claimed in claim 1 in which the means forexpanding the inner and outer shields include a separate pressure sourcefor each of said shields.

10. A vehicle safety device as claimed in claim 9 in which the fillermaterial is a gas carried in at least one capsule located in themounting means.

11. A vehicle safety device as claimed in claim 10 in which saidmounting means include a head rest, and the capsule is carried in saidhead rest.

12. A vehicle safety device as claimed in claim 1 in which the outershield is made up from a series of tubes to which the inner shield whichcomprises a series of vesicles is connected.

13. A vehicle safety device as claimed in claim 1 including means forreleasing the expandible element from said mounting means after it hasbeen expanded.

14. A vehicle safety device as claimed in claim 13 including means foroperating the release means after a time delay.

15. A vehicle safety device as claimed in claim 1 in which said mountingmeans includes a releaseable anchorage member carrying the expandibleelement, and

said mounting means being reloadable with a replacement anchorage memberand element after the original element has been operated and removed.

16. A vehicle safety device as claimed in claim 1 in which said mountingmeans includes a housing receiving the expandible element when in itsretracted position, the housing being closed by a removeable cap, andmeans for pressurizing the interior of the housing prior to release ofthe cap.

17. A vehicle safety device as claimed in claim 16 in which the housingis pressurised by filler material used to expand the outer shield.

18. A vehicle safety device as claimed in claim 1 in which the outershield has free edge areas and carries reinforcing bands at said edgeareas.

19. A vehicle safety device as claimed in claim 1 in which the mountingmeans carries an impact cushion which is expandible in the oppositedirection to the projection of the element to provide protection for aperson behind the safety device.

20. A vehicle safety device as claimed in claim 1 in which the safetydevice includes a sensor for effecting operation of the device, thesensor including a piezo crystal which is subjected to mechanicaldeformation.

21. A vehicle safety device as claimed in claim 1 in which the safetydevice includes a sensor for actuating a signal generator to effectoperation of the device, and wherein the signal generator actuates asignal interrupter or chopper which performs a time delay in a sequenceof signals for activating the operating means.

22. A vehicle safety device as claimed in claim 21 including a monitorwhich allows actuation of the device only at predetermined conditions ofvehicle motion.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 753,576 Dated August 21, 1973 Inventor (5) John F Gorman It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In the heading, insert the following:

Foreign Application Priority Data Sept. 29, 1970 Great Britain 46,294/70Signed and sealed this 19th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM PO-IOSO (10-69) USCOMM'DC 60316P69 h U.S. GOVERNMENTPRINTING OFFICE 2 I969 0-365-334,

1. A vehicle safety device comprising an expandible composite element, mounting means for mounting said element in a vehicle in an inoperative retracted position relative to an occupant seat, said element including an expansible and projectable outer shield carried by said mounting means for projection therefrom, means connected to said outer shield for expanding said outer shield and projecting said outer shield to a shielding position in spaced relation to an occupant seat to provide for a initial shielding of an occupant, said element also including an inner shield carried by said outer shield for projection therefrom, and means for expanding said inner shield relative to said outer shield towards an occupant seat after expansion of said outer shield has been initiated to provide for a further shielding of an occupant.
 2. A vehicle safety device as claimed in claim 1 in which the element is arranged to extend around an occupant to be protected to encapsulate him, the inner shield expanding inwardly to closely contact him.
 3. A vehicle safety device as claimed in claim 2 wherein said mounting means is rigidly secured to a vehicle seat.
 4. A vehicle safety device as claimed in claim 3, said mounting means including a main structural member part of which extends above the back of the seat and which carries the expandible element.
 5. A vehicle safety device as claimed in claim 4 in which the main structural member above the seat provides a safety structure for preventing the vehicle structure caving in around the seat.
 6. A vehicle safety device as claimed in claim 5 in which the main structural member is in the form of a hoop and from which the element expands forwardly around the seat to a part spherical shape, the inner surface of the inner shield being contoured to approximate to the frontal and side shape of a human body from the head down to waist level when the element is fully expanded.
 7. A vehicle safety device as claimed in claim 1 in which the fill material is a foam solution.
 8. A vehicle safety device as claimed in claim 1 including means for delaying expansion of the inner shield until the outer shield is at least partially expanded.
 9. A vehicle safety device as claimed in claim 1 in which the means for expanding the inner and outer shields include a separate pressure source for each of said shields.
 10. A vehicle safety device as claimed in claim 9 in which the filler material is a gas carried in at least one capsule located in the mounting means.
 11. A vehicle safety device as claimed in claim 10 in which said mounting means include a head rest, and the capsule is carried in said head rest.
 12. A vehicle safety device as claimed in claim 1 in which the outer shield is made up from a series of tubes to which the inner shield which comprises a series of vesicles is connected.
 13. A vehicle safety device as claimed in claim 1 including means for releasing the expandible element from said mounting means after it has been expanded.
 14. A vehicle safety device as claimed in claim 13 including means for operating the release means after a time delay.
 15. A vehicle safety device as claimed in claim 1 in which said mounting means includes a releaseable anchorage member carrying the expandible element, and said mounting means being reloadable with a replacement anchorage member and element after the original element has been operated and removed.
 16. A vehicle safety device as claimed in claim 1 in which said mounting means includes a housing receiving the expandible element when in its retracted position, the housing being closed by a removeable cap, and means for pressurizing the interior of the housing prior to release of the cap.
 17. A vehicle safety device as claimed in claim 16 in which the housing is pressurised by filler material used to expand the outer shield.
 18. A vehicle safety device as claimed in claim 1 in which the outer shield has free edge areas and carries reinforcing bands at said edge areas.
 19. A vehicle safety device as claimed in claim 1 in which the mounting means carries an impact cushion which is expandible in the opposite direction to the projection of the element to provide protection for a person behind the safety device.
 20. A vehicle safety device as claimed in claim 1 in which the safety device includes a sensor for effecting operation of the device, the sensor including a piezo crystal which is subjected to mechanical deformation.
 21. A vehicle safety device as claimed in claim 1 in which the safety device includes a sensor for actuating a signal generator to effect operation of the device, and wherein the signal generator actuates a signal interrupter or chopper which performs a time delay in a sequence of signals for activating the operating means.
 22. A vehicle safety device as claimed in claim 21 including a monitor which allows actuation of the device only at predetermined conditions of vehicle motion. 